The project will explore the feasibility of novel highly sensitive detectors for advanced THz electronic systems using 2D and 3D gratings with nanometer feature sizes and implemented using deep submicron silicon technology. For the first time, a new configuration of plasma wave detector array elements with symmetrical sources and two symmetrical gate fingers will be implemented and a multi scale approach ensuring a plasmonic resonance with each element of the array and an electromagnetic resonance within the entire array will be used. If successful, this feasibility study will develop and validate a new pathway for the subwavelength coupling of THz radiation with the two dimensional electron gas or fluid in solid-state systems and will enable a new generation of THz electronics systems with revolutionary impact on the US airport security systems and biomedical applications.
Principal Investigator will fabricate and characterize the FINFET detector prototypes and develop software tools for design and optimization of electronics systems using such detectors to prove the feasibility of this new approach. The project will explore the feasibility of new nanoscale FIN FET elements to form the THz detection units with optimum boundary conditions that have never been achieved before. These will be done by using opposing current flows in these four terminal detector units. The project will include investigation of the THz interaction with and coupling to these elements, study their sensitivity, noise, temperature dependencies, and Noise Equivalent Power. This will be done using three dimensional electromagnetic simulation and nanoscale THz imaging. The silicon FIN FET elements will be combined into nanostructured arrays to capture the entire THz beam to prove the feasibility of silicon based plasmonic THz technology.
The intellectual merit of the proposed project will be in proving feasibility of multi scale nonlinear active nanostructure arrays with elements of new, previously unexplored type for solving fundamental scientific problems of THz radiation interaction with solid and biological matter at femtosecond time intervals and nanometer and atomic scales.
The broader impact of the project will be in gaining understanding new fundamental physics of active nonlinear multi scale nanostructures enabling the development of THz electronics with orders of magnitude better performance at a fraction of the cost of existing systems; in seeding the development of new multibillion dollar THz electronics industry with applications in medicine, home land security, industrial controls, space exploration, and defense; in creating hundreds of thousands of new high-tech American jobs and in training the next generation of scientists and engineers through THz related new curriculum and outreach at all levels - from K to 12 to post graduate education. Principal Investigator will engage the REU undergraduate students and will give lectures and demonstrations in local high schools.
Terahertz electronics will enable multiple applications in medicine, biotechnology, defense, homeland security, and industrial controls. This project focused on Nanometer size field effect transistors and transistor arrays that can operate as efficient resonant or broadband THz detectors, mixers, phase shifters and frequency multipliers at frequencies far beyond their fundamental cut-of frequencies. We have developed a large signal model that allowed us to determine the dynamic range of these detectors and, for the first time, designed and implemented prototypes of integrated circuits using the THz plasmonic transistors as circuit elements. Our analysis of plasmonic FET detectors showed that that Si NMOS, GaN HEMT, and InGaAs HEMT detectors with 22 nm feature size could operate efficiently at frequencies close to 1 THz, 10 THz, and 20 THz, respectively. For 130 nm features size, the efficiency peaks at 0.1 THz, 0.2 THz, 0.8 THz for Si, GaN, and InGaAs devices, respectively. A new semiconductor material – graphene – has promise of outperforming more conventional materials in THz applications. We proposed the concept of terahertz (THz) uncooled bolometer based on the array of graphene layers and nanoribbons. The proposed bolometer can surpass the hot-electron bolometers on the base of traditional semiconductor heterostructures. We also developed the theory of a THz plasmonic laser that will provide a robust, inexpensive source of THz radiation.